Substrate Surface Treatment Research Articles

Effect of surface roughness of electroplating chromium coated steel on bonding strength of polymer coated steel

The effect of surface roughness of electroplating chromium coated steel on bonding strength of polymer coated steel has been investigated in this paper. The experimental results have shown that the electroplating chromium coated steel with different surface roughness could be obtained through the substrate surface treatment before the electroplating process. The peeling test results have shown that the peeling force of the polymer coated steel would increase with the increase of surface roughness of the electroplating chromium coated steel, but the increase rate would become slow gradually. With the increase of surface roughness of electroplating chromium coated steel, the PET film would be damaged locally and some polymer residues would remain on the electroplating chromium coated steel; when the bonding force is large enough, the plating shedding would occur on the electroplating chromium coated steel. With the appearance of the polymer residues and the occurrence of plating shedding, the failure mode of polymer coated steel would transform from adhesion failure mode to the mixed failure mode.

Experimental investigation of adhesion strength of dental ceramic to Ti6Al4V alloy fabricated by milling and selective laser melting

The aim of the present paper is to investigate the bond strength of dental ceramic to Ti6Al4V alloy fabricated by milling and selective laser melting (SLM). The adhesion strength is studied by 3-point flexural test of samples with porcelain coating. Two groups of specimens are manufactured by milling and SLM. Four different surface treatments are used before porcelain application - no surface treatment (control), sandblasting and application of bonding agent on untreated and sandblasted surfaces. The coating of leucite-reinforced glass-ceramic is manufactured on the one side of the samples. It is found that the adhesion strength of the porcelain coating to the titanium alloy produced by both methods has close values: 17.63 – 30.89 MPa for the milled and 22.12 – 31.04 MPa for the SLM alloy. The surface treatments of the metal substrate have different effect on the adhesion strength. Sandblasting and combined treatment increase the adhesion strength of the porcelain to the milled samples, but decrease that in the SLM ones. The application of the given bonding agent decreases the adhesion strength of the ceramic to the Ti6Al4V alloy produced by both technologies. In the milled alloy, the highest adhesion strength is in the sandblasted samples, followed by these with combined treatment, while for the SLM samples, the adhesion strength in the control group is the highest, followed by the sandblasted samples. Milled samples treated with the given bonding agent, and SLM specimens with combined surface treatment do not meet the required 25 MPa of the standard.

Исследование влияния обработки поверхности Si-подложек на морфологию слоев GaP, полученных методом плазмохимического атомно-слоевого осаждения

Investigations of atomic-layer deposition of GaP layers on Si substrates with different orientations and with different preliminary surface treatment have been carried out. The deposition of GaP was carried out by the method of plasma enhanced atomic-layer deposition using in situ treatment in argon plasma. It was shown that at the initial stage of the growth of GaP layers on precisely oriented (100) Si substrates and with misorientation, two-dimensional growth occurs both after chemical and plasma surface treatment. Upon growth on (111) substrates, after plasma treatment of the surface, a transition to three-dimensional growth is observed, at which the size of islands reaches 30–40 nm. The smallest root-mean-square roughness of the surface of the growing GaP layers (<0.1 nm) was achieved for (100) substrates with a misorientation of 4 °. The GaP layers grown on (100) substrates had a roughness of ~ 0.1 nm, and on substrates with the (111) orientation - 0.12 nm. It was found that the surface treatment of Si substrates with the (100) orientation in hydrogen plasma leads to a slight increase in the surface roughness of growing GaP layers (0.12–0.14 nm), which is associated with the effect of inhomogeneous etching of silicon in hydrogen plasma. When treating the (100) silicon surface in argon plasma, the surface roughness does not change significantly in comparison with the chemical surface treatment. On the surface of substrates with preliminary deposition of an epitaxial Si layer with a thickness of 4 nm, the morphology of GaP layers is the same as in the case of using hydrogen plasma.

Impact of silicon wafer surface treatment on the morphology of GaP layers produced by plasma enhanced atomic layer deposition

Investigations of atomic-layer deposition of GaP layers on Si substrates with different orientations and with different preliminary surface treatment have been carried out. The deposition of GaP was carried out by the method of plasma enhanced atomic-layer deposition using in situ treatment in argon plasma. It was shown that at the initial stage of the growth of GaP layers on precisely oriented (100) Si substrates and with misorientation, two-dimensional growth occurs both after chemical and plasma surface treatment. Upon growth on (111) substrates, after plasma treatment of the surface, a transition to three-dimensional growth is observed, at which the size of islands reaches 30-40 nm. The smallest root-mean-square roughness of the surface of the growing GaP layers (<0.1 nm) was achieved for (100) substrates with a misorientation of 4o. The GaP layers grown on (100) substrates had a roughness of ~0.1 nm, and on substrates with the (111) orientation --- 0.12 nm. It was found that the surface treatment of Si substrates with the (100) orientation in hydrogen plasma leads to a slight increase in the surface roughness of growing GaP layers (0.12-0.14 nm), which is associated with the effect of inhomogeneous etching of silicon in hydrogen plasma. When treating the (100) silicon surface in argon plasma, the surface roughness does not change significantly in comparison with the chemical surface treatment. On the surface of substrates with preliminary deposition of an epitaxial Si layer with a thickness of 4 nm, the morphology of GaP layers is the same as in the case of using hydrogen plasma. Keywords: PECVD, ALD, silicon, gallium phosphide

Effect of Ald Al2o3 Passivation Layer Thickness on the Surface Treatment of Direct-Bonded Copper Substrates: Wetting, Oxidation, and Mechanical Property Analyses

Effect of Ald Al2o3 Passivation Layer Thickness on the Surface Treatment of Direct-Bonded Copper Substrates: Wetting, Oxidation, and Mechanical Property Analyses

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Investigations of atomic-layer deposition of GaP layers on Si substrates with different orientations and with different preliminary surface treatment have been carried out. The deposition of GaP was carried out by the method of plasma enhanced atomic-layer deposition using in situ treatment in argon plasma. It was shown that at the initial stage of the growth of GaP layers on precisely oriented (100) Si substrates and with misorientation, two-dimensional growth occurs both after chemical and plasma surface treatment. Upon growth on (111) substrates, after plasma treatment of the surface, a transition to three-dimensional growth is observed, at which the size of islands reaches 30–40 nm. The smallest root-mean-square roughness of the surface of the growing GaP layers (<0.1 nm) was achieved for (100) substrates with a misorientation of 4 °. The GaP layers grown on (100) substrates had a roughness of ~ 0.1 nm, and on substrates with the (111) orientation - 0.12 nm. It was found that the surface treatment of Si substrates with the (100) orientation in hydrogen plasma leads to a slight increase in the surface roughness of growing GaP layers (0.12–0.14 nm), which is associated with the effect of inhomogeneous etching of silicon in hydrogen plasma. When treating the (100) silicon surface in argon plasma, the surface roughness does not change significantly in comparison with the chemical surface treatment. On the surface of substrates with preliminary deposition of an epitaxial Si layer with a thickness of 4 nm, the morphology of GaP layers is the same as in the case of using hydrogen plasma.

Effect of substrate surface treatment on the hydrothermal synthesis of zinc oxide nanostructures

In this investigation, ZnO nanostructures were coated via hydrothermal process on glass substrate surfaces, which were treated by acidic and alkaline solutions. Furthermore, the ZnO structure was doped by different amounts of Al+3 ions to investigate the microstructural variation. Characteristics of the samples by XRD and SEM analyses confirmed the formation of different morphologies and various crystal sizes for the nanostructured ZnO on the substrates including nanoflower, nanorod, and nanopanel morphologies. Furthermore, XRD results showed that the Zn2+ concentration was a crucial factor in changing the grain size. EDS analysis confirmed the uniform distribution of Al dopant, while the FTIR spectra revealed the presence of Al–O and Zn–O stretching bonds in the coatings. The results confirmed that the sample, which was etched by fused NaOH had a uniform and compacted structure. Moreover, it was evident the proposed treatment and synthesis process was successful in the formation of uniform nanostructured ZnO film on the glass substrate without the requirement for seed layer deposition.

Electromagnetic interference shielding effectiveness of polypyrrole-silver nanocomposite films on silane-modified flexible sheet

The conventional electromagnetic interference (EMI) shielding materials are being gradually replaced by a new generation of supported conducting polymer composites (CPC) films due to their many advantages. This work presents a contribution on the effects of silane surface–modified flexible polypyrrole-silver nanocomposite films on the electromagnetic interference shielding effectiveness (EMI-SE). Thus, the UV-polymerization was used to in-situ deposit the PPy-Ag on the biaxial oriented polyethylene terephthalate (BOPET) flexible substrates whose surfaces were treated by 3-aminopropyltrimethoxysilane (APTMS). X-ray Photoelectron Spectroscopy (XPS) analyzes confirmed the APTMS grafting procedure. Structural, morphological, thermal, and electrical characteristics of the prepared films were correlated to the effect of substrate surface treatment. Thereafter, EMI-SE measurements of the elaborated films were carried out as per ASTM D4935 standard for a wide frequency band extending from 50 MHz to 18 GHz. The obtained results confirmed that the APTMS-treated BOPET film exhibit higher EMI shielding performance and better electrical characteristics compared to the untreated film. In fact, a 32% enhancement of EMI-SE was noted for the treated films compared to the untreated ones. Overall, these results put forward the role played by the surface treatment in strengthening the position of flexible PPy-Ag supported films as high-performance materials in electronic devices and electromagnetic interference shielding applications.

Optimization of the Rework of Bended OLED Displays by Surface-Energy Control

Recent display technology has changed substantially from flat-type displays to bended displays. As a result, the lamination process for bonding the panel substrates and bended window glass has become difficult due to the changes in display shape, and the use of optically clear adhesive (OCA) makes it impossible to rework defective substrates due to residue problems. Therefore, it is necessary to research and develop a substrate-surface treatment that maintains the initial adhesion and is reusable via the complete removal of impurities during delamination in order to enable rework. In this paper, the possibility of maintaining adhesive force and reusing substrates was confirmed through the surface treatment of substrates and OCA using various materials. We found that a surface coating and a cooling treatment of additional substrates completely removed the impurities that remained on the substrates during reworking. These results could contribute to improving lamination-process technology and the productivity of the various forms of next-generation displays that are currently under development.

Rapid and tunable growth of a well-ordered hexagonal nanoporous anodic aluminum oxide (AAO) structure by two-step high-temperature anodization

In this study, we have developed a swift and well-ordered growth of a nanoporous anodic aluminum oxide (AAO) structure using two-step high temperature anodization of the pure aluminum substrate. The pre-anodization surface treatment of the aluminum substrate assisted in the formation of well-organized nanoporous structures. The two-step anodization process was performed in 0.3 mol/L of oxalic acid at 20 °C with 40 and 45 V to obtain tunable pore diameters. The high temperature of the electrolyte solution facilitated the rapid growth of the nanoporous AAO structure. The top surface image of AAO shows a well-ordered nanoporous structure with an average pore diameter of 70 nm at 40 V and 100 nm at 45 V. The SEM cross-sectional view also illustrates the well-ordered nano-channel and the elemental mapping elaborates the presence of aluminum and oxygen. The thickness of the nanoporous AAO structure was determined using SEM for three anodization time spans (20, 24, and 28 h), in which an increasing trend was observed. The fabricated AAO has a higher thickness and a well-ordered nanoporous structure, which shows that it can be used as a template for fabricating nanostructured materials.

Effect of different types of substrate surface treatments on the graphene device performance

Graphene–substrate interface is very crucial for analyzing graphene device performance. In this article, we have shown how the graphene device performance got affected because of different types of substrate surface treatment techniques used before graphene transfer. For fabrication of graphene devices, monolayer chemical vapor deposition (CVD) graphene was transferred onto SiO2 grown thermally on Si substrate. Forming gas annealed SiO2/Si shows better device performance as compared with as‐grown SiO2 on Si substrate. A further effect of oxygen plasma and argon plasma cleaning of SiO2 surface before graphene transfer was investigated. Forming gas annealing improves the performance and plasma treatment degrade the graphene devices' performance.

Effect of surface treatment methods on the interfacial behavior of fiber metal laminate based on WE43 magnesium alloy

The surface treatment of the metal substrate has a significant effect on the adhesion between the metal sheet and fiber/epoxy prepreg. The effect of the surface treatment methods, including sandpaper abrasion, phosphating treatment, anodizing and plasma electrolytic oxidation (PEO), on the surface morphology, surface energy and shear strength of WE43 magnesium alloy was analyzed in this study. The surface roughness is noted to have a significant effect on the wettability of WE43 magnesium alloy. The roughness and surface energy of the phosphated WE43 magnesium alloy are observed to be the largest among the four surface treatment methods, and the corresponding values are 4.17 and 70.8 mJ/m2, respectively. The lap-shear tensile tests reveal that WE43 magnesium alloy treated by the PEO process possesses the highest shear strength. Overall, the shear strength of the samples after phosphating treatment, anodizing and PEO treatment is noted to improve by 46%, 61% and 116% respectively, as compared with the sample treated by sandpaper abrasion. The observed superior shear properties after PEO treatment have been attributed to the cylindrical pores conducive to the infiltration of the epoxy resin during the curing process, thus, enhancing the adhesion between WE43 magnesium alloy sheet and epoxy resin. Additionally, the shear fracture mechanism was also analyzed in detail.

Fractal-Percolation Structure Architectonics in Sol-Gel Synthesis.

It was developed a new technique to assess micro- and mesopores with sizes below a few nanometers. The porous materials with hierarchical fractal-percolation structure were obtained with the sol-gel method. The tetraethoxysilane hydrolysis and polycondensation reactions were performed in the presence of salts as the sources of metal oxides. The porous materials were obtained under spinodal decomposition conditions during application of the polymer sol to the substrate surface and thermal treatment of the structures. The model is based on an enhanced Kepler net of the 4612 type with hexagonal cells filled with a quasi-two-dimensional projection of the Jullien fractal after the 2nd iteration. The materials obtained with the sol-gel method were studied using the atomic force microscopy, electron microscopy, thermal desorption, as well as an AutoCAD 2022 computer simulation of the percolation transition in a two-component system using the proposed multimodal model. Based on the results obtained, a new method was suggested to assess micro- and mesopores with sizes below a few nanometrs, which cannot be analyzed using the atomic force microscopy and electron microscopy.

Improvement in bond behavior and thermal properties of carbon fiber-reinforced polymer strengthened steel structures

This study focused on the bond strength and environmental durability of carbon fiber-reinforced polymer (CFRP)-strengthened steel structures, by investigating the improvements in the surface treatment of the steel substrate, thermal properties of the epoxy resin, and curing process of the composite. The results showed that the steel–adhesive interfacial bonding behavior can be improved by increasing the surface roughness and using a low-viscosity primer to enhance the wettability. During the initial curing, a lower ambient temperature during the gel time can reduce the porosity of the multi-CFRP laminate. However, raising the initial curing temperature is advantageous for the mechanical and thermal properties of the composite. In addition, the thermal properties of the epoxy matrix were clarified by differential scanning calorimetry tests, based on which isothermal curing degree curves of the system were drawn. The results demonstrated that post-curing at 80 °C is vital for increasing the glass transition temperature, which is also appropriated for the primer. Finally, the moisture and thermal effects on the deterioration of the adhesive joint were examined by conducting short-period aging tests in immersion and wet–dry cyclic environments, during which delamination strength reduction and failure mode transformation were observed.

Influence of surface treatment of resin composite substrate on the load-bearing capacity under fatigue of lithium disilicate monolithic simplified restorations

This study evaluated the influence of surface treatments of resin composite substrate on the fatigue behavior of adhesively cemented lithium disilicate glass-ceramic simplified restorations. CAD/CAM lithium disilicate ceramic blocks were shaped into discs (N = 60, Ø = 10 mm; thickness = 1.0 mm). Resin composite discs (N = 60, Ø = 10 mm, thickness = 2 mm) were allocated into four groups considering the “surface treatment” factor: Ctrl – no surface treatment; Bur – grinding with coarse diamond bur (#3101G, KG Sorensen); PA – etching with 37% phosphoric acid (15 s); AA – air abrasion with alumina particles (45 μm, 10 mm distance, 2.8 bars, 10 s). The surface topography, the roughness, the fractal dimension (estimated by the box-counting method) and the contact angle analyses were performed after the surface treatments. The lithium disilicate discs were etched (5% hydrofluoric acid, 20 s), silanized and adhesively cemented (Multilink N, Ivoclar Vivadent) on the resin composite discs. The samples (bonded restoration set) were subjected to a step-stress fatigue test at 20 Hz, 10,000 cycles/step with a step-size of 100 N applied on the ceramic surface, having ceramic up and resin composite down. Fractographic analysis was performed. The fatigue data (Fatigue Failure Load – FFL; and Cycles for Failure – CFF) were analyzed by Kaplan Meier with Mantel-Cox log-rank post-hoc tests (α = 0.05). No statistical difference for fatigue performance could be found among the groups (FFL means: 820–867 N; CFF means: 53,195–61,090 cycles). The bur group showed higher surface roughness and contact angle values. The PA group has the highest average fractal dimension. Therefore, the resin composite surface treatment induces topographical changes, however, it has no effect on the fatigue behavior of lithium disilicate restorations.

Hard Anodization Film on Carbon Steel Surface by Thermal Spray and Anodization Methods.

In this paper, we used two mass-produced industrial technologies, namely, thermal spraying and anodization methods, to enhance the surface characteristics of AISI 1045 medium carbon steel for use in special environments or products. The anodic film can effectively improve the surface properties of carbon steel. A sequence of treatments of the carbon steel substrate surface that consist of sandblasting, spraying the aluminum film, annealing, hot rolling, cleaning, grinding, and polishing can increase the quality of the anodized film. This paper proposes an anodization process for the surface of carbon steel to increase the corrosion resistance, hardness, color diversification, and electrical resistance. The resulting surface improves the hardness (from 170 HV to 524 HV), surface roughness (from 1.26 to 0.15 μm), coloring (from metal color to various colors), and corrosion resistance (from rusty to corrosion resistant). The electrochemical corrosion studies showed that the AISI 1045 steel surface with a hard anodized film had a lower corrosion current density of 10−5.9 A/cm2 and a higher impedance of 9000 ohm than those of naked AISI 1045 steel (10−4.2 A/cm2 and 150 ohm) in HCl gas.

A closed-circulation system for chemical polishing of the 1.3-GHz single-cell copper cavity substrate for niobium sputtering

A 1.3-GHz copper cavity chemical polishing system has been developed by the Institute of High Energy Physics. It has been used for the surface treatment of copper cavity substrates before the niobium sputtering. The system uses the SUBU polishing agent developed by the European Organization for Nuclear Research (CERN), which is a four-component mixed acid with a working temperature of 72∘C. For environmental protection reasons, the system adopts a fully closed-cycle mode, which prevents acid volatility at high temperatures to the ambient environment. Based on the sample experiments, polishing steps have been optimized to avoid as much as possible the oxidation phenomenon which is easily introduced to the copper cavity inner surface, including cooling, dilution, and passivation process. Finally, the surface treatment process of the closed polishing system was determined based on the optimized polishing steps, and the oxygen isolation protection method after treatment was put forward to accommodate long-distance transportation of the copper cavity before coating. The experimental results show that the surface of the copper cavity after chemical polishing was smooth and bright with an average roughness of 0.12 μm.

Regimes of substrates processing and deposition nanofilms using the laser-plasma method

The physical processes occurring in a laser-plasma source is used for deposition nanostructures. The laser-plasma source is an erosion laser plume of the target material and a substrate located in a vacuum chamber. It has been proposed to place a grid between the laser target and the substrate. A negative potential is applied to the grid relative to the laser target to smoothly adjust the parameters of the particles deposited on the substrate. As a result, a particles flow is formed after a grid. This particle flow is predominantly consisting of ions. The energy of the ions can be reliably and smoothly controlled by applying a positive potential to the grid relative to the substrate. It has been experimentally proved method for deposition of nanofilms using ion beams from the laser plasma. It has been shown that different regimes of substrate surface treatment can be implemented in the laser-plasma source for deposition nanostructures. Using this source, you can sequentially clean the surface of the substrate without depressurizing the vacuum chamber, and create a pseudodiffusion layer of the laser target material near the surface layer of the substrate. It will allow producing it possible to obtain highly adhesive nanofilms with predetermined parameters.

Comprehensive study on the electrochemical, morphological, and adhesion properties of Cr-free thin film: with and without polyurethane coating

The deposition process of titanium-based conversion coating (Ti-CC) and the influence of this layer on adhesion strength and anticorrosion performance of polyurethane coatings were investigated. Aluminum 2024-T3 (Al-2024) substrates were treated by Ti-CC at different pH (2.5, 3.5, 4.5, 5.5), Ti concentrations (0.5, 1, 5, 10 g/L), and immersion times (0, 30, 120, 300, 600 s). Electrochemical impedance spectroscopy (EIS) and direct current polarization (DC) were used to evaluate the anticorrosion performance of the different samples. The microstructure, chemical composition, and surface characteristics of the samples were studied by field emission scanning electron microscopy (FE-SEM), energy-dispersive X-ray spectroscopy, atomic force microscopy, X-ray photoelectron spectroscopy (XPS), and contact angle measuring device. The anticorrosion resistance and adhesion property of the polyurethane coating were examined by salt spray and pull-off tests, respectively. Results demonstrated that the surface treatment of the Al-2024 substrate in titanium bath enhanced the anticorrosion performance of the substrate. According to the results of EIS and DC polarization, the sample treated in (Ti = 1 g/L, t = 2 min and pH = 4.5) showed the highest anticorrosion resistance (22.90 kohm cm2) and lower current density (icorr = 2.05 µA/cm2). The FE-SEM images revealed more uniformity and compact structure at the optimized condition. XPS spectrum demonstrated that the Al-2024 substrate was covered by aluminum and titanium oxide/hydroxide after surface treatment. Contact angle measurement indicated that surface treatment of the substrate by Ti-CC caused an increase in hydrophobicity of the surface. The Ti-CC improved the adhesion strength and anticorrosion performance of the polyurethane coating applied on Al-2024 substrates.

СОЗДАНИЕ ПРОЧНЫХ КЛЕЕВЫХ КОНСТРУКЦИЙ ИЗ ДРЕВЕСИНЫ НА ОСНОВЕ ФИЗИКОМОДЕФИЦИРОВАННЫХ КЛЕЕВ

In the past few decades, gluing technologies have been widely used in woodworking, which significantly expand the range of new products. Bonding of products with adhesives is used in the manufacture of furniture, parquet, load-bearing and enclosing structures, door and window blocks, prefabricated houses and many other products. The main criteria for the quality of glued wood joints is the cohesive and adhesive strength of the glued joint. To date, a number of technologies have been developed to improve the strength of glued wood joints. In order to increase the strength of the adhesive bond of wood, technologists propose methods of variation by such factors as temperature, pressure during curing of the adhesive joint, the purity of the surface treatment of substrates, and the thickness of the adhesive layer. A large amount of work and substantial financial costs are spent on creating new brands of adhesives. However, the requirements for glued timber products are not solved by the proposed gluing technologies and new brands of glues. First of all, this concerns the widely used glue wood structures (CDC), as a rule, operating in difficult conditions with high mechanical loads. To solve the problem of increasing the reliability of glue wood structures, instead of domestic imported, but more expensive adhesives are often used. To a certain extent, the creation of more high-strength adhesive joints has recently also been solved by the use of methods for modifying domestic adhesives exposed to irradiation with magnetic and electric fields, as well as ultrasound.